1. Field of the Invention
This invention pertains generally to field repair fixtures, and more particularly to fixtures for supporting the rotor of an electric generator during field repair operations.
2. Related Art
Electric generator rotor field work is generally carried on on or near the turbine deck and typically involves moving the shrunk-on components, machining stress relief grooves, fits, elimination of turn-to-turn shorts, checking hydrogen seals, and reassembly of all the shrunk-on components. To accomplish this work, all machining and runout measurements are done in a Vee-block setup, where the centerline of the generator is approximately 52 inches (132.08 cm) off the floor. Keeping the centerline low has certain advantages in minimizing machining chatter during the heavy machining needed to enlarge rotor vent slots. Furthermore, all of the machining drive systems are set to operate at this approximate height. However, the power rollers, which are required for reassembling of the shrunk-on components operate with the rotor centerline approximately 63 (160.02 cm) inches above the turbine deck. This height difference has until now necessitated the transfer of the rotor from the Vee-blocks, to power rollers, to Vee-blocks, and then finally back to the power rollers. This involved using an overhead crane up to four times. Scheduling the crane, which was also required for removal/reassembly of the shrunk-on components added to delays in the refurbishment operation, which is costly.
Accordingly, a new electric generator repair fixture is desired that can minimize the use of the overhead crane in the course of refurbishment of a generator rotor.
Furthermore, a new electric generator rotor repair fixture is desired that can vary the height of the centerline of the rotor to accommodate different refurbishment operations.
Additionally, a new electric generator rotor repair fixture is desired that can make maximum use of existing components.